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Purpose: To elucidate whether pro-inflammatory cytokines might influence the commitment of intervertebral disc (IVD)- and ligamentum flavum (LF)-derived progenitor cells toward either osteogenesis or adipogenesis, specifically Interleukin-1β (IL-1β), IL-19, and IL-20., Methods: Sixty patients with degenerative spondylolisthesis and lumbar or lumbosacral spinal stenosis were included in the study. Injuries to the spine, infections, and benign or malignant tumors were excluded. From nine patient samples, IVD- and LF-derived cells were isolated after primary culture, and two clinical samples were excluded due to mycoplasma infection. The effects of IL-1β, IL-19, as well as IL-20 in regulating osteogenic and adipogenic differentiation in vitro were investigated., Results: Primary IVD- and LF-derived cells were found to have a similar cell morphology and profile of surface markers (CD44, CD90, and CD105) as placenta-derived mesenchymal stem cells (MSCs). Primary IVD/LF cells have a high capacity to differentiate into osteocytes and adipocytes. IL-19 had a tendency to promote adipogenesis. IL-20 inhibited osteogenesis and promoted adipogenesis; IL-1β promoted osteogenesis but inhibited adipogenesis., Conclusion: IL-1β, IL-19, and IL-20 impact the adipogenic and osteogenic differentiation of IVD-derived and LF-derived cells. Modulating the expression of IL-1β, IL-19, and IL-20 provides a potential avenue for controlling cell differentiation of IVD- and LF-derived cells, which might have beneficial effect for degenerative spondylolisthesis and spinal stenosis., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Study Design: Retrospective radiologic analysis., Objective: The aim was to investigate if lateral flexion-extension radiographs identify additional cases of degenerative cervical spondylolisthesis (DCS) that would be missed by obtaining solely neutral upright radiographs, and determine the reliability of magnetic resonance imaging (MRI) in diagnosis., Summary of Background Data: DCS and instability can be a cause of neck pain, radiculopathy, and even myelopathy. Standard anteroposterior and lateral radiographs and MRI of the cervical spine will identify most cervical spine pathology, but spondylolisthesis and instability are dynamic issues. Standard imaging may also miss DCS in some cases., Methods: We compared the number of patients who demonstrated cervical spondylolisthesis on lateral neutral and flexion-extension radiographs in addition to MRI. We used established criteria to define instability as ≥2 mm of listhesis on neutral imaging, and ≥1 mm of motion between flexion-extension radiographs., Results: A total of 111 patients (555 cervical levels) were analyzed. In all, 41 patients (36.9%) demonstrated cervical spondylolisthesis on neutral and/or flexion-extension radiographs. Of the 77 levels of spondylolisthesis, 17 (22.1%) were missed on neutral radiographs ( P ,0.05). Twenty levels (26.0%) were missed when flexion-extension radiographs were used alone ( P =0.02). Twenty-nine levels (37.7%) of DCS identified on radiograph were missed by MRI ( P =0.004)., Conclusions: Lateral flexion-extension views can be useful in the diagnosis of DCS. These views provide value by identifying a significant cohort of patients that would be undiagnosed based on neutral radiographs alone. Moreover, MRI missed 38% of DCS cases identified by radiographs. Therefore, lateral radiographs can be a useful adjunct to neutral radiographs and MRI when instability is suspected or if these imaging modalities are unable to identify the source of a patient's neck or arm pain., Competing Interests: The authors declare no conflict of interest., (Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc.)

Lumbar spondylolisthesis is usually asymptomatic. However, symptomatic spondylolisthesis results in back and/or leg pain such as radicular syndrome or neurogenic claudication. Variation in symptoms is caused by different types of spondylolisthesis. Lytic spondylolisthesis, most common at L5S1, is caused by spondylolysis of the pars interarticularis. This results in foraminal nerve compression and radicular symptoms. Degenerative spondylolisthesis, most common at L4L5 in patients >50 years old, is caused by slippage of the vertebral body and lamina, resulting in lumbar spinal stenosis and neurogenic claudication. Iatrogenic spondylolisthesis develops in 1.6-32.0% of patients after decompression surgery, causing recurrent neurogenic symptoms. It is important to understand the main symptoms patients experience: back or leg pain. In both cases, the preferred treatment is conservative. Surgery is only an option if patients have persistent/progressive leg pain. Shared decision-making is necessary to select the most accurate surgery for each individual patient while also taking into account age, comorbidities and symptoms. Further research is necessary to determine the advantages of each surgery in order to improve advice to patients.

Background: Degenerative spondylolisthesis (DS) occurs mostly at L4. However, there are a small number of patients in whom it occurs only at L3. Accordingly, past reports elucidating the factors of DS have been primarily concerned with L4 DS, and few reports are available on DS at L3. The objective of this study was to compare the differences between lumbar spinal stenosis patients with or without L3 DS and to identify the possible pathological mechanisms of their L3 DS., Methods: Among the 369 patients with lumbar spinal stenosis who underwent lumbar surgery, we assessed 25 patients who had DS only at L3 and compared them against 50 other age- and gender-matched lumbar spinal stenosis patients without any DS. The following radiographic parameters: pelvic incidence, sacral slope, pelvic tilt, L3 slope, L4 slope, L5 slope, and lumbar lordosis were measured on radiographs. The orientation of facet joints and disc heights were measured via computed tomography., Results: Imaging findings showed that the L3, L4, and L5 slopes in the L3 DS group were significantly greater than in the non-DS group, and only L3/4 facet joints in the L3 DS group were significantly more sagittally oriented than in the control group. The number of patients with low disc heights at L4/5 in the L3 DS group was significantly greater than in the control group., Conclusions: The results suggested that the greater lumbar slope, including L3 together with more sagittally oriented facet joints only at L3/4 and not at L4/5, may lead to DS only at L3., (Copyright © 2018 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.)

Background: Degenerative spondylolisthesis (DS) and lumbar spinal stenosis (LSS) are the most common degenerative spinal diseases. The evaluating of spinopelvic sagittal alignment of the two diseases using pelvic radius (PR) technique have not been reported. The purpose of this study was to use PR measurement technique to compare the differences in spinopelvic sagittal alignment between DS and LSS., Methods: A total of 145 patients with DS or LSS were retrospectively reviewed. Seventy patients with DS (DS group) and 75 age-matched patients with LSS (LSS group) were enrolled. Spinopelvic parameters including pelvic angle (PA), regional lumbopelvic lordosis (PR-L1, PR-L2, PR-L3, PR-L4 and PR-L5), total lumbopelvic lordosis (PR-T12), pelvic morphology (PR-S1), sagittal vertical axis from the C7 plumb line (SVA), lumbar lordosis (LL), thoracic kyphosis (TK), L4 slope and L5 slope were assessed in the two groups. Several parameters of DS and LSS group were compared with the normal population (NP)., Results: The PR-L4, PR-L5 and PR-S1 in the DS group were significantly smaller than those in the LSS group. There was no difference in PR-T12 between the DS group and NP (p > 0.05), while PR-T12 of the LSS group were significantly lower (p < 0.01). Degree of correlations among spinopelvic parameters differed between the two groups. PR-T12 of the DS group was more strongly correlated with PA (r = -0.829, p < 0.001) than with LL (r = 0.664, p < 0.001), TK (r = 0.582, p < 0.001). PR-T12 of the LSS group was more strongly correlated with LL (r = 0.854, p < 0.001), TK (r = 0.616, p < 0.001) than with PA (r = -0.582, p < 0.001)., Conclusions: PR-L4 and PR-L5 may be the predisposing factors for DS development. Spinopelvic morphology differed in patients with DS and LSS compared to NP. The compensatory mechanisms to maintain spinopelvic sagittal alignment in DS and LSS patients may be different., (Copyright © 2018 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.)

Study Design: Retrospective cohort study., Objective: The objective was to prove the association between anatomic pelvis parameters and specific types of lumbar spinal degeneration., Summary of Background Data: Different spinopelvic sagittal profile types are suggested to be associated with specific degenerative lumbar spine pathologies. Because pelvic morphology plays a key role defining the spinal shape as well as its load and function it thereby potentially predisposes the development of spinal degeneration., Materials and Methods: Patients with symptomatic lumbar spinal degeneration who were surgically treated in 2 spine departments from March 2011 until August 2016 were included in this retrospective analysis. Single-level degenerative pathologies were classified as lumbar disc herniation (LDH), degenerative disc disease (DDD), lumbar spinal stenosis (LSS), and degenerative spondylolisthesis (DSPL). The constant anatomic pelvic parameters pelvic incidence (PI), pelvic radius (PR), and sacral table angle (STA) were assessed in lateral radiographs of the lumbar spine and compared between the pathologies., Results: In total, 249 patients were assigned to the LDH (n=73), DDD (n=67), LSS (n=42), and DSPL (n=67) groups. Group comparisons revealed significant differences in the anatomic pelvic parameters PR (LDH, 139.5±10.8 mm; DDD, 135.9±14.0 mm; LSS, 127.8±14.3 mm; DSPL, 135.8±12.7 mm; P<0.001), PI (LDH, 53.1±10.0 degrees; DDD, 50.0±9.9 degrees; LSS, 54.5±9.6 degrees; DSPL, 57.1±10.8 degrees; P=0.001), and STA (LDH, 95.3±12.7 degrees; DDD, 105.4±9.0 degrees; LSS, 105.9±11.5 degrees; DSPL, 98.6±9.5 degrees; P<0.001). Post hoc tests indicated significant differences between the PR of the LSS group and that of all other subgroups (P<0.012), the PI of the DDD group and that of DSPL (P<0.001), and the STA of the LDH/DSPL groups and that of the LSS/DDD group (P<0.005)., Conclusions: We found all the constant anatomic parameters to be specific for distinct types of degeneration, suggesting pelvis shape is a predisposing factor for their development., Level of Evidence: Level III.

Background: The nonfusion pedicle-screw system Dynesys stabilization (DS) for lumbar degenerative disease aims to better preserve range of motion (ROM) than fixation and fusion systems. However, decreased ROM and unexpected facet fusion at the index level were observed after DS was applied with unknown etiology. The aim of this study is using radiologic parameters to explain the phenomenon of facet arthrodesis., Methods: The patients who underwent surgery for L4-5 spinal stenosis were sorted retrospectively into 2 groups: DS and microdiskectomy (MicD). Radiologic parameters including facet degeneration, evaluated by computed tomography or magnetic resonance image, and ROM, evaluated by dynamic radiographs, were compared perioperatively. A linear regression model was fitted to data points to calculate correlation over time. Postoperative facet arthrodesis at the index level was detected by computed tomography. Functional outcomes were also compared between groups., Results: A total of 61 patients (DS-to-MicD = 38:23) were followed 36.9 ± 16.8 months postoperatively. After surgery, both groups of patients had significant clinical improvement without difference between the 2 groups (all P > 0.05). In the DS group, significantly decreased ROM was observed after 24-month follow-up (P < 0.05). The correlation coefficient of facet degeneration over time and the facet fusion rate in the DS group were both significantly higher than in the MicD group (both P < 0.05)., Conclusions: The patients who underwent DS for L4-5 grade 1 spondylolisthesis experienced significantly reduced ROM and a positive correlation of facet degeneration over time postoperatively. The limited ROM at the index level could be a potential risk of facet degeneration and cause unexpected arthrodesis., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Purpose: Compared to the ligamentum flavum (LF), morphology of the epidural membrane (EM) and the periradicular fibrous tissue (PRFT) has been largely ignored in studies of lumbar spinal stenosis (LSS). The aim of this prospective study was to elucidate the morphologies and clinical importance of the EM and PRFT in LSS., Methods: Before starting this study, neural compressive EM (c-EM) and PRFT (c-PRFT) were defined as follows based on our microsurgical experience and a literature review. The c-EM is a constriction band or membrane obstructing dural tube expansion, and the c-PRFT is a fibrous tissue that compresses the nerve root and/or restricts its mobility. This study enrolled 134 patients who underwent microscopic decompression at L4/5. The morphologies of each patient's EM and PRFT were observed and recorded. Specimens were obtained from randomly selected patients for histological evaluation., Results: The EM and PRFT exhibited a wide morphological spectrum, from a fine strand to a substantial membrane. The c-EM alone was observed in four cases, the c-PRFT alone in 37 cases, and both in three cases. The c-PRFT was more frequently observed in patients with degenerative spondylolisthesis than in those without olisthesis (P < 0.05). Several cases exhibited interesting histological findings including many small arteries, chondrometaplasia, ganglion-like cyst formation, and hyalinized collagen fibers., Conclusions: Some EM and PRFT transform into degenerative and substantial fibrous tissues during the process of symptomatic LSS development. Such morphological and histological changes can cause dural tear, symptomatic epidural hematoma, and/or inadequate decompression.

Objective: To assess the predictive factors for subjective improvement with nonsurgical treatment in consecutive patients with lumbar spinal stenosis (LSS)., Materials and Methods: Patients with LSS were enrolled from 17 medical centres in Japan. We followed up 274 patients (151 men; mean age, 71 ± 7.4 years) for 3 years. A multivariable logistic regression model was used to assess the predictive factors for subjective symptom improvement with nonsurgical treatment., Results: In 30% of patients, conservative treatment led to a subjective improvement in the symptoms; in 70% of patients, the symptoms remained unchanged, worsened, or required surgical treatment. The multivariable analysis of predictive factors for subjective improvement with nonsurgical treatment showed that the absence of cauda equina symptoms (only radicular symptoms) had an odds ratio (OR) of 3.31 (95% confidence interval [CI]: 1.50-7.31); absence of degenerative spondylolisthesis/scoliosis had an OR of 2.53 (95% CI: 1.13-5.65); <1-year duration of illness had an OR of 3.81 (95% CI: 1.46-9.98); and hypertension had an OR of 2.09 (95% CI: 0.92-4.78)., Conclusions: The predictive factors for subjective symptom improvement with nonsurgical treatment in LSS patients were the presence of only radicular symptoms, absence of degenerative spondylolisthesis/scoliosis, and an illness duration of <1 year.

Unlabelled: To evaluate the association of redundant nerve roots of cauda equina (RNRCE) with the degree of lumbar spinal stenosis (LSS) and with spondylolisthesis., Method: After Institutional Board approval, 171 consecutive patients were retrospectively enrolled, 105 LSS patients and 66 patients without stenosis. The dural sac cross-sectional area (CSA) was measured on T2w axial MRI at the level of L2-3, L3-4 and L4-5 intervertebral discs. Two blinded radiologists classified cases as exhibiting or not RNRCE in MRI. Intra- and inter-observer reproducibility was assessed., Results: RNRCE were associated with LSS. RRNCE was more frequent when maximum stenosis<55 mm2. Substantial intra- observer agreement and moderate inter-observer agreement were obtained in the classification of RNRCE. Spondylolisthesis was identified in 27 patients and represented increased risk for RRNCE., Conclusion: LSS is a risk factor for RNRCE, especially for dural sac CSA<55 mm2. LSS and spondylolisthesis are independent risk factors for RNRCE.

Patients presenting with stenosis associated with a spondylolisthesis will often describe signs and symptoms consistent with neurogenic claudication, radiculopathy, and/or low-back pain. The primary objective of surgery, when deemed appropriate, is to decompress the neural elements. As a result of the decompression, the inherent instability associated with the spondylolisthesis may progress and lead to further misalignment that results in pain or recurrence of neurological complaints. Under these circumstances, lumbar fusion is considered appropriate to stabilize the spine and prevent delayed deterioration. Since publication of the original guidelines there have been a significant number of studies published that continue to support the utility of lumbar fusion for patients presenting with stenosis and spondylolisthesis. Several recently published trials, including the Spine Patient Outcomes Research Trial, are among the largest prospective randomized investigations of this issue. Despite limitations of study design or execution, these trials have consistently demonstrated superior outcomes when patients undergo surgery, with the majority undergoing some type of lumbar fusion procedure. There is insufficient evidence, however, to recommend a standard approach to achieve a solid arthrodesis. When formulating the most appropriate surgical strategy, it is recommended that an individualized approach be adopted, one that takes into consideration the patient's unique anatomical constraints and desires, as well as surgeon's experience.

Study Design: Retrospective analysis of kinematic magnetic resonance (MR) images., Objective: To elucidate the distribution and risk factors associated with missed dynamic stenosis in cervical spine., Summary of Background Data: Motion of the cervical spine is widely accepted to be associated with cervical spondylotic myelopathy; however, the distribution and the risk factors for dynamic spinal stenosis are not well understood., Methods: A total of 435 symptomatic patients (2610 cervical segments) obtained upright kinematic MR images in neutral, flexion, and extension postures. Spinal cord compression (SCC), spondylolisthesis, disc bulging, angular motion, translational motion, disc degeneration grade, Modic changes, segmental alignment, and developmental stenosis were all evaluated. Cervical segments C2-C3 to C7-T1 were divided into 2 groups, determined by the presence of SCC. After excluding segments with SCC in the neutral position, a multivariate logistic regression model was used to evaluate for associated risk factors of SCC in flexion and extension that were not present in the neutral position., Results: SCC in neutral position was observed in 5.3% (139/2610) of segments. After excluding these segments, missed dynamic stenosis was found in 8.3% (204/2471) of segments in extension and 1.6% (40/2471) in flexion. Missed dynamic stenosis in both extension and flexion was most frequent at C5-C6. Multivariate logistic regression analysis for dynamic stenosis in extension revealed that disc bulge greater than 2.4 mm, angular motion greater than 4.8°, moderate and severe disc degeneration, segmental kyphosis, and developmental stenosis were significant risk factors. In flexion, significant risk factors were a disc bulge of 1.9 mm or greater, moderate to severe disc degeneration, and segmental kyphosis., Conclusion: Dynamic cord compression was most common at the C5-C6 segment. Cervical segments with greater disc bulge, more severe disc degeneration, greater angular motion, segmental kyphosis, and developmental stenosis may be at risk for missed dynamic stenosis.

Individual pelvic sacral angle was measured, compared and analyzed for the 6 male and female adults who were diagnosed with lumbar spinal stenosis, foraminal stenosis and mild spondylolisthesis in accordance with spinal parameters, pelvic parameters and occlusion state of sacroiliac joint presented by the author of this thesis based on the fact that the degree of lumbar excessive lordosis that was one of the causes for lumbar pain was determined by sacral slope. The measured values were compared with the standard values of the average normal range from 20 s to 40 s of normal Koreans stated in the study on the change in lumbar lordosis angle, lumbosacral angle and sacral slope in accordance with the age by Oh et al. [5] and sacral slope and pelvic sacral slope of each individual of the subjects for measurement were compared. Comparing the difference between the two tilt angles possessed by an individual is a comparison to determine how much the sacroiliac joint connecting pelvis and sacral vertebrae compensated and corrected the sacral vertebrae slope by pelvic tilt under the condition of synarthrodial joint.Under the condition that the location conforming to the line in which the sagittal line of gravity connects with pelvic ASIS and pubic pubic tuberele is the neutral location of pelvic tilt, sacral slope being greater than pelvic sacral slope means pelvic anterior tilting, whereas sacral slope being smaller than pelvic sacral slope means pelvic posterior tilting. On that account, male B, female A and female C had a pelvic posterior tilting of 16 degrees, 1 degree and 5 degrees respectively, whereas male A, male C and female B had a pelvic anterior tilting of 3 degrees, 9 degrees and 4 degrees respectively. In addition, the 6 patients the values of lumbar lordosis angle, lumbosacral angle and sacral slope that were almost twice as much as the normal standard values of Koreans. It is believed that this is because the pelvic sacral slope maintaining an angle that is slightly greater than the normal range by being located in the lowest end of spine considering that the compensation for pelvic tilt, in other words, pelvic limb is not much causes an excess of lumbar lordosis angle. The meaning of this study based on these results is to prove that PSA is one of the important factors that fundamentally determine lumbar curvature. And this is because it is definitely required to have a study on the guideline for appropriate posture and life habit to the maintenance and management of ideal PSA before the end of growth phase and also the exercise therapy and adjustment for the control of PSA.

Object: It is not known whether adding fusion to lumbar decompression is necessary for all patients undergoing surgery for degenerative lumbar spondylolisthesis with symptomatic stenosis. Determining specific radiographic traits that might predict delayed instability following decompression surgery might guide clinical decision making regarding the utility of up-front fusion in patients with degenerative Grade I spondylolisthesis., Methods: Patients with Grade I degenerative lumbar spondylolisthesis (3-14 mm) with symptomatic stenosis were prospectively enrolled from a single site between May 2002 and September 2009 and treated with decompressive laminectomy without fusion. Patients with mechanical back pain or with gross motion (> 3 mm) on flexion-extension lumbar radiographs were excluded. The baseline radiographic variables measured included amount of slippage, disc height, facet angle, motion at spondylolisthesis (flexion-extension), and sagittal rotation angle. Data were analyzed using multivariate forward selection stepwise logistic regression, chi-square tests, Student t-test, and ANOVA., Results: Forty patients were enrolled and treated with laminectomy without fusion, and all patients had complete radiographic data sets that were available for analysis. Reoperation was performed in 15 (37.5%) of 40 patients, with a mean follow-up duration of 3.6 years. Reoperation was performed for pain caused by instability at the index level in all 15 cases. Using multivariate stepwise logistic regression with a threshold p value of 0.35, motion at spondylolisthesis, disc height, and facet angle were predictors of reoperation following surgery. Facet angle > 50° was associated with a 39% rate of reoperation, disc height > 6.5 mm was associated with a 45% rate of reoperation, and motion at spondylolisthesis > 1.25 mm was associated with a 54% rate of reoperation. Patients with all 3 risk factors for instability had a 75% rate of reoperation, whereas patients with no risk factors for instability had a 0% rate of reoperation (p = 0.14)., Conclusions: Patients with motion at spondylolisthesis > 1.25 mm, disc height > 6.5 mm, and facet angle > 50° are more likely to experience instability following decompression surgery for Grade I lumbar spondylolisthesis. Identification of key risk factors for instability might improve patient selection for decompression without fusion surgery.

Object: Lumbar spinal stenosis (LSS) is a common condition that leads to significant disability, particularly in the elderly. Current therapeutic modalities for LSS have certain drawbacks when applied to this patient population. The object of this study was to define the 12-month postoperative outcomes and complications of pedicle-lengthening osteotomies for symptomatic LSS., Methods: A prospective, single-treatment clinical pilot study was conducted. A cohort of 19 patients (mean age 60.9 years) with symptomatic LSS was treated by pedicle-lengthening osteotomy procedures at 1 or 2 levels. All patients had symptoms of neurogenic claudication or radiculopathy secondary to LSS and had not improved after a minimum 6-month course of nonoperative treatment. Eleven patients had a Meyerding Grade I degenerative spondylolisthesis in addition to LSS. Clinical outcomes were measured using the Oswestry Disability Index (ODI), Zurich Claudication Questionnaire (ZCQ), 12-Item Short-Form Health Survey (SF-12), and a visual analog scale (VAS). Procedural variables, neurological outcomes, adverse events, and radiological imaging (plain radiographs and CT scans) were collected at the 1.5-, 3-, 6-, 9-, and 12-month time points., Results: The pedicle-lengthening osteotomies were performed through percutaneous approaches with minimal blood loss in all cases. There were no operative complications. Four adverse events occurred during the follow-up period. Clinically, significant improvement was observed in the mean values of each of the outcome scales (comparing preoperative and 12-month values): ODI scores improved from 52.3 to 28.1 (p < 0.0001); the ZCQ physical function domain improved from 2.7 to 1.8 (p = 0.0021); the SF-12 physical component scale improved from 27.0 to 37.9 (p = 0.0024); and the VAS score for leg pain while standing improved from 7.2 to 2.7 (p < 0.0001). Imaging studies, reviewed by an independent radiologist, showed no evidence of device subsidence, migration, breakage, or heterotopic ossification. Thin-slice CT documented healing of the osteotomy site in all patients at the 6-month time point and an increase in the mean cross-sectional area of the spinal canal of 115%., Conclusions: Treatment of patients with symptomatic LSS with a pedicle-lengthening osteotomy procedure provided substantial enlargement of the area of the spinal canal and favorable clinical results for both disease-specific and non-disease-specific outcome measures at the 12-month time point. Future studies are needed to compare this technique to alternative therapies for lumbar stenosis.

Spinal stenosis and degenerative spondylolisthesis share many symptoms and the same treatment, but their causes remain unclear. Bone mineral density has been suggested to play a role. The aim of this study was to investigate differences in spinal bone density between spinal stenosis and degenerative spondylolisthesis patients. 81 patients older than 60 years, who underwent DXA-scanning of their lumbar spine one year after a lumbar spinal fusion procedure, were included. Radiographs were assessed for disc height, vertebral wedging, and osteophytosis. Pain was assessed using the Low Back Pain Rating Scale pain index. T-score of the lumbar spine was significantly lower among degenerative spondylolisthesis patients compared with spinal stenosis patients (-1.52 versus -0.52, P = 0.04). Thirty-nine percent of degenerative spondylolisthesis patients were classified as osteoporotic and further 30% osteopenic compared to only 9% of spinal stenosis patients being osteoporotic and 30% osteopenic (P = 0.01). Pain levels tended to increase with poorer bone status (P = 0.06). Patients treated surgically for symptomatic degenerative spondylolisthesis have much lower bone mass than patients of similar age treated surgically for spinal stenosis. Low BMD might play a role in the development of the degenerative spondylolisthesis, further studies are needed to clarify this.

Purpose: The measurement of transverse pedicle width is still recommended for selecting a screw diameter despite being weakly correlated with the minimum pedicle diameter, except in the upper lumbar spine. The purpose of this study was to reveal the difference between the minimum pedicle diameter and conventional transverse or sagittal pedicle width in degenerative lumbar spines., Methods: A total of 50 patients with degenerative lumbar disorders without spondylolysis or lumbar scoliosis of >10° who preoperatively underwent helical CT scans were included. The DICOM data of the scans were reconstructed by imaging software, and the transverse pedicle width (TPW), sagittal pedicle width (SPW), minimum pedicle diameter (MPD), and the cephalocaudal inclination of the pedicles were measured., Results: The mean TPW/SPW/MPD values were 5.46/11.89/5.09 mm at L1, 5.76/10.44/5.39 mm at L2, 7.25/10.23/6.52 mm at L3, 9.01/9.36/6.83 mm at L4, and 12.86/8.95/7.36 mm at L5. There were significant differences between the TPW and MPD at L3, L4, and L5 (p < 0.01) and between the SPW and MPD at all levels (p < 0.01)., Conclusions: The MPD was significantly smaller than the TPW and SPW at L3, L4, and L5. The actual measurements of the TPW were not appropriate for use as a direct index for the optimal pedicle screw diameter at these levels. Surgeons should be careful in determining pedicle screw diameter based on plain CT scans especially in the lower lumbar spine.

Background and Purpose: Axial loaded MR imaging, which can simulate the spinal canal of patients in a standing position, demonstrates a significant reduction of the DCSA compared with conventional MR imaging and provides valuable imaging findings in the assessment of the lumbar spinal canal. The purpose of this study was to compare the DCSA on axial loaded MR imaging between patients with DS and SpS., Materials and Methods: Eighty-eight consecutive patients were divided into DS and SpS groups. DCSA on conventional MR imaging and axial loaded MR imaging and changes in the DCSA induced by axial loading were compared between DS and SpS groups. The prevalence of a significant change (>15 mm(2)) in the DCSA was compared between the 2 groups., Results: Axial loaded MR imaging demonstrated significantly smaller DCSA in the DS group (35 ± 22 mm(2)) than in the SpS group (50 ± 31 mm(2)), though conventional MR imaging did not show any differences between the 2 groups. The change in the DCSA induced by axial loading was significantly larger in the DS group (17 ± 12 mm(2)) compared with the SpS group (8 ± 8 mm(2)). The prevalence of a >15-mm(2) change in the DCSA was significantly higher in the DS group (62.5%) than in the SpS group (16.7%) (odds ratio, 8.33; 95% confidence interval, 3.09-22.50)., Conclusions: Axial loaded MR imaging demonstrated significantly larger changes in the DCSA in patients with DS compared those with SpS. A significant change in the DCSA was more frequently observed in patients with DS. Axial loaded MR imaging may therefore be a more useful tool to decrease the risk of underestimating the spinal canal narrowing in patients with DS than in those with SpS.

The outcome of less invasive surgical techniques in comparison to traditional surgical techniques has been the source of debate. In this retrospective study, 51 patients who had undergone posterior lumbar fusion along with bilateral decompression were enrolled. Twenty-one patients underwent fusion using a standard, midline open technique (open group) and 30 patients underwent fusion using a mini-open technique, with a small, central incision for the decompression and bilateral paramedian incisions for the posterolateral fusion and placement of cannulated pedicle screws (mini-open group). Surgical variables were compared between the 2 groups. Patients in both groups experienced significant improvements in leg pain at 12 months, with a reduction in visual analog scale scores from 7.6 to 2.4 in the open group, and 7.8 to 2.3 in the mini-open group. There were no statistical differences between the groups in the magnitude of improvement of either the visual analog scale or Oswestry Disability Index scores. Operative times, blood loss, and length of hospitalization failed to show statistically significant differences between the groups, although there was a trend toward less blood loss and shorter hospitalization in the mini-open group. Fusion results and complications were similar between the 2 groups. Both techniques resulted in similarly statistically significant improvements in pain and clinical function.

Background and Purpose: MRI is the modality of choice when diagnosing spinal stenosis but it also shows that stenosis is prevalent in asymptomatic subjects over 60. The relationship between preoperative health-related quality of life, functional status, leg and back pain, and the objectively measured dural sac area in single and multilevel stenosis is unknown. We assessed this relationship in a prospective study., Patients and Methods: The cohort included 109 consecutive patients with central spinal stenosis operated on with decompressive laminectomy or laminotomy. Preoperatively, all patients completed the questionnaires for EQ-5D, SF-36, Oswestry disability index (ODI), estimated walking distance and leg and back pain (VAS). The cross-sectional area of the dural sac was measured at relevant disc levels in mm², and spondylolisthesis was measured in mm. For comparison, the area of the most narrow level, the number of levels with dural sac area < 70 mm², and spondylolisthesis were studied., Results: Before surgery, patients with central spinal stenosis had low HRLQoL and functional status, and high pain levels. Patients with multilevel stenosis had better general health (p = 0.04) and less leg and back pain despite having smaller dural sac area than patients with single-level stenosis. There was a poor correlation between walking distance, ODI, the SF-36, EQ-5D, and leg and back pain levels on the one hand and dural sac area on the other. Women more often had multilevel spinal stenosis (p = 0.05) and spondylolisthesis (p < 0.001). Spondylolisthetic patients more often had small dural sac area (p = 0.04) and multilevel stenosis (p = 0.06)., Interpretation: Our findings indicate that HRQoL, function, and pain measured preoperatively correlate with morphological changes on MRI to a limited extent.

Study Design: As-treated analysis of the Spine Patient Outcomes Research Trial., Objective: To compare baseline characteristics and surgical and nonoperative outcomes in degenerative spondylolisthesis (DS) and spinal stenosis (SpS) patients stratified by predominant pain location (i.e., leg vs. back)., Summary of Background Data: Evidence suggests that DS and SpS patients with predominant leg pain may have better surgical outcomes than patients with predominant low back pain (LBP)., Methods: The DS cohort included 591 patients (62% underwent surgery), and the SpS cohort included 615 patients (62% underwent surgery). Patients were classified as leg pain predominant, LBP predominant, or having equal pain according to baseline pain scores. Baseline characteristics were compared between the 3 predominant pain location groups within each diagnostic category, and changes in surgical and nonoperative outcome scores were compared for 2 years. Longitudinal regression models including baseline covariates were used to control for confounders., Results: Among DS patients at baseline, 34% had predominant leg pain, 26% had predominant LBP, and 40% had equal pain. Similarly, 32% of SpS patients had predominant leg pain, 26% had predominant LBP, and 42% had equal pain. DS and SpS patients with predominant leg pain had baseline scores indicative of less severe symptoms. Leg pain predominant DS and SpS patients treated surgically improved significantly more than LBP predominant patients on all primary outcome measures at 1 and 2 years. Surgical outcomes for the equal pain groups were intermediate to those of the predominant leg pain and LBP groups. The differences in nonoperative outcomes were less consistent. Conclusion. Predominant leg pain patients improved significantly more with surgery than predominant LBP patients. However, predominant LBP patients still improved significantly more with surgery than with nonoperative treatment.

Background: Decompression and spinal fusion have been generally recommended for spinal stenosis associated with low-grade degenerative spondylolisthesis (DS), although this is still controversial. The purpose of the present study is to analyze the clinical and radiological outcomes of interspinous dynamic stabilization using the Locker (WINNOVA co, Seoul, Korea) for lumbar canal stenosis with grade I DS., Methods: The authors performed a retrospective review of 23 consecutive patients who underwent single level decompression and the Locker application for lumbar canal stenosis with grade I DS and were followed up for at least 2 years. Excluded were those with DS grade II or higher and DS combined with foraminal disc herniation/stenosis. The mean age of patients at the time of surgery was 62.1 years (range: 45-81 years)., Results: There were no complications in the perioperative period. At a mean follow-up duration of 28.3 months (range: 24-32 months), visual analogue scale scores for back pain, leg pain, and Oswestry disability index had decreased significantly; from 4.6, 7.2, and 38.5% to 2.4, 2.6, and 15.3%, respectively. Clinical success was achieved in 87% of the patients. The mean percentage of slippage did not change significantly. The mean sagittal rotation angle significantly decreased from 9.7 to 6.5 degrees (p=0.01). One patient (4.3%) underwent secondary fusion surgery due to persistent pain., Conclusions: Decompression and interspinous dynamic stabilization using the Locker yielded favorable clinical and radiological outcomes for lumbar canal stenosis with grade I DS and could be an alternative for spinal fusion. However, further long-term follow-up studies are necessary., (Georg Thieme Verlag KG Stuttgart . New York.)

Objective: To analyze the factors affecting the occurrence of adjacent segment degeneration (ASD) after lumbar internal fixation., Methods: The clinical data of 147 surgical patients with lumbar disc herniation, lumbar spinal stenosis and lumbar spodylolisthesis undergoing surgeries between January 2002 and July 2007 in our hospital were reviewed. The correlations of gender, range of fixation, position of fixation, and characteristic of the adjacent disc to the occurrence of ASD were analyzed., Results: The patients were followed up for a mean of 30-/+10 months (18-84 months). The incidence of ASD was 13.6% in these patients, occurring all at the cephalad adjacent segment. The presence of preoperative degeneration of the adjacent disc gave rise to increased risk of ASD following the surgery (chi(2)=6.272, P=0.012), and multivariate analysis indicated that preoperative adjacent disc degeneration was a risk factor for postoperative ASD (P=0.046), but gender, range of fusion and site of fusion were not the risk factors., Conclusion: Presence of adjacent segment degeneration before the operation is associated with a significantly increased risk of postoperative ASD.

Background: Diabetes mellitus is a multi-organ disorder affecting many types of connective tissues, including bone and cartilage. Certain skeletal changes are more prevalent in diabetic patients than in non-diabetic individuals. A possible association of diabetes mellitus and lumbar spinal stenosis has been raised., Objectives: To compare the prevalence of diabetes mellitus in patients with spinal stenosis, degenerative disk disease or osteoporotic vertebral fractures., Methods: A cross-sectional analysis was performed of 395 consecutive patients diagnosed with spinal stenosis, degenerative disk disease or osteoporotic vertebral fractures. All the patients were examined by one senior author in the outpatient orthopedic clinic of a large general hospital between June 2004 and January 2006 and diagnosed as having lumbar spinal stenosis (n=225), degenerative disk disease (n=124), or osteoporotic vertebral fractures (n=46)., Results: The prevalence of diabetes mellitus in the three groups (spinal stenosis, osteoporotic fracture, degenerative disk disease) was 28%, 6.5% and 12.1%, respectively, revealing a significantly higher prevalence in the spinal stenosis group compared with the others (P=0.001). The higher prevalence of diabetes in the stenotic patients was unrelated to the presence of degenerative spondylolisthesis., Conclusions: There is an association between diabetes and lumbar spinal stenosis. Diabetes mellitus may be a predisposing factor for the development of lumbar spinal stenosis.

Delayed complications following lumbar spine fusion may occur amongst which is adjacent segment degeneration (ASD). Although interspinous implants have been successfully used in spinal stenosis to authors' knowledge such implants have not been previously used to reduce ASD in instrumented lumbar fusion. This prospective controlled study was designed to investigate if the implantation of an interspinous implant cephalad to short lumbar and lumbosacral instrumented fusion could eliminate the incidence of ASD and subsequently the related re-operation rate. Groups W and C enrolled initially each 25 consecutive selected patients. Group W included patients, who received the Wallis interspinous implant in the unfused vertebral segment cephalad to instrumentation and the group C selected age-, diagnosis-, level-, and instrumentation-matched to W group patients without interspinous implant (controls). The inclusion criterion for Wallis implantation was UCLA arthritic grade UCLA grade II in the adjacent two segments cephalad to instrumentation. All patients suffered from symptomatic spinal stenosis and underwent decompression and 2-4 levels stabilization with rigid pedicle screw fixation and posterolateral fusion by a single surgeon. Lumbar lordosis, disc height (DH), segmental range of motion (ROM), and percent olisthesis in the adjacent two cephalad to instrumentation segments were measured preoperatively, and postoperatively until the final evaluation. VAS, SF-36, and Oswestry Disability Index (ODI) were used. One patient of group W developed pseudarthrosis: two patients of group C deep infection and one patient of group C ASD in the segment below instrumentation and were excluded from the final evaluation. Thus, 24 patients of group W and 21 in group C aged 65+ 13 and 64+ 11 years, respectively were included in the final analysis. The follow-up averaged 60 +/- 6 months. The instrumented levels averaged 2.5 + 1 vertebra for both groups. All 45 spines showed radiological fusion 8-12 months postoperatively. Lumbar lordosis did not change postoperatively. Postoperatively at the first cephalad adjacent segment: DH increased in the group W (P = 0.042); ROM significantly increased only in group C (ANOVA, P < 0.02); olisthesis decreased both in flexion (P = 0.0024) and extension (P = 0.012) in group W. The degeneration or deterioration of already existed ASD in the two cephalad segments was shown in 1 (4.1%) and 6 (28.6%) spines in W and C groups, respectively. Physical function (SF-36) and ODI improved postoperatively (P < 0.001), but in favour of the patients of group W (P < 0.05) at the final evaluation. Symptomatic ASD required surgical intervention was in 3 (14%) patients of group C and none in group W. ASD remains a significant problem and accounts for a big portion of revision surgery following instrumented lumbar fusion. In this series, the Wallis interspinous implant changed the natural history of ASD and saved the two cephalad adjacent unfused vertebra from fusion, while it lowered the radiographic ASD incidence until to 5 years postoperatively. Longer prospective randomized studies are necessary to prove the beneficial effect of the interspinous implant cephalad and caudal to instrumented fusion. We recommend Wallis device for UCLA degeneration I and II.

A clear consensus for the optimal surgical treatment for spinal stenosis associated with degenerative spondylolisthesis (DS) has not appeared. In general, decompression and fusion are recommended. However, the symptoms of spinal stenosis are the main complaints in almost all patients with DS, and whether or not routine concomitant fusion is necessary in the surgical treatment for DS is still discussed controversially. The authors have treated almost all the patients with spinal stenosis associated with DS by microendoscopic posterior decompression (MEPD) procedures since 2001. In the present study, we examined the minimum 2-year outcome in 37 patients surgically treated with the MEPD procedures for spinal stenosis associated with DS. At the mean of 38 months after surgery, the overall results were excellent in 54% of the patients, good in 19%, fair in 13.5%, and poor in 13.5%, based on the Japanese Orthopedic Association lumbar score, a visual analogue scale, and the Roland-Morris disability questionnaire. Although the progression of spondylolisthesis and the increase of segmental sagittal motion after surgery were seen in 7 patients (19%), only one patient required secondary fusion during the follow-up period. A sufficient decompression with the preservation of the posterior structures of the spine was observed in almost the patients after surgery. In conclusion, the MEPD is a minimally invasive procedure developing a sufficient decompression with the preservation of the spinal stability. Thus, the MEPD is one of the useful procedures in the surgical treatment of spinal stenosis associated with DS. However, further follow-up studies should be performed to evaluate the long-term outcome for evaluation of the true validity of the MEPD for DS.

With the aging of the population, the number of patients suffering from progressive lumbar spinal stenosis with symptomatic neurogenic intermittent claudication is projected to increase. Unfortunately, these patients are limited to a choice between nonsurgical conservative care and more invasive decompressive surgical procedures such as laminectomy with or without fusion. The X STOP interspinous process decompression system is a commercially available device that provides a minimally invasive alternative treatment, an intermediate option within the continuum of care for these patients. The X STOP is appropriate for patients with moderately severe functional impairment whose symptoms are exacerbated in extension and relieved in flexion. Implanted between the spinous processes without disrupting the normal anatomical structures, the X STOP limits narrowing of the spinal canal and neural foramina by reducing extension at the symptomatic level(s). In this report the author details the approved indications for use of the X STOP and discusses several illustrative cases.

Background: Symptomatic lumbar spinal stenosis produces gradually progressive back and leg pain with standing and walking, relieved by sitting or lying. One of the uncommon symptoms is involuntary intermittent penile erection due to spinal canal stenosis. This symptom is very rare and often forgotten when history is taken., Methods: In this case report, a patient suffering from intermittent priapism due to degenerative spinal canal stenosis and spondylolisthesis is described. On admission his symptoms were intermittent neurogenic claudication and involuntary erection provoked by walking a short distance., Results: Bilateral laminectomy and posterior fusion was performed. His symptoms resolved over the first postoperative days., Conclusion: Cauda equina compression due to LSS may rarely cause intermittent priapism. This rare symptom should not be forgotten when taking the patient's history and should also be kept in mind during follow-up.

Study Design: Prospective observational cohorts., Objective: To describe sociodemographic and clinical features, and nonoperative (medical) resource utilization before enrollment, in patients who are candidates for surgical intervention for intervertebral disc herniation (IDH), spinal stenosis (SpS), and degenerative spondylolisthesis (DS) according to SPORT criteria., Summary of Background Data: Intervertebral disc herniation, spinal stenosis, and degenerative spondylolisthesis with stenosis are the three most common diagnoses of low back and leg symptoms for which surgery is performed. There is a paucity of descriptive literature examining large patient cohorts for the relationships among baseline characteristics and medical resource utilization with these three diagnoses., Methods: The Spine Patient Outcomes Research Trial (SPORT) conducts three randomized and three observational cohort studies of surgical and nonsurgical treatments for patients with IDH, SpS, and DS. Baseline data include demographic information, prior treatments received, and functional status measured by SF-36 and the Oswestry Disability Index (ODI-AAOS/Modems version). The data presented represent all 1,411 patients (743 IDH, 365 SpS, 303 DS) enrolled in the SPORT observational cohorts. Multiple logistic regression was used to generate independent predictors of utilization adjusted for sociodemographic variables, diagnosis, and duration of symptoms., Results: The average age was 41 years for the IDH group, 64 years for the SpS group, and 66 years for the DS group. At enrollment, IDH patients presented with the most pain as reported on the SF-36 (BP 26.3 vs. 33.2 SpS and 33.8 DS) and were the most impaired (ODI 51 vs. 42.3 SpS and 41.5 DS). IDH patients used more chiropractic treatment (42% vs. 33% SpS and 26% DS), had more Emergency Department (ED) visits (21% vs. 7% SpS and 4% DS), and used more opiate analgesics (49% vs. 29% SpS and 27% DS). After adjusting for age, gender, diagnosis, education, race, duration of symptoms, and compensation, Medicaid patients used significantly more opiate analgesics (58% Medicaid vs. 41% no insurance, 42% employer, 33% Medicare, and 32% private) and had more ED visits compared with other insurance types (31% Medicaid vs. 22% no insurance, 16% employer, 3% Medicare, and 11% private)., Conclusion: IDH patients appear to have differences in sociodemographics, resource utilization, and functional impairment when compared with the SpS/DS patients. In addition, the differences in resource utilization for Medicaid patients may reflect differences in access to care. The data provided from these observational cohorts will serve as an important comparison to the SPORT randomized cohorts in the future.

Objective: To evaluate the outcome of two methods for stabilization and fusion: posterolateral fusion and circumferential fusion involving posterior lumbar interbody fusion for lumbar stenosis with Grades 1 and 2 lumbar spondylolisthesis., Methods: From April 1998 to April 2003, 45 patients suffering from lumbar stenosis with low degree lumbar spondylolisthesis treated in our hospital were retrospectively reviewed and assigned to two groups. Among them, 24 patients (group A) were treated with instrumented posterolateral fusion and 21 patients (group B) with instrumented circumferential fusion. The two groups were compared for clinical and radiological outcomes., Results: All patients were followed up for 12 to 72 months. In group A, results showed preoperative clinical symptoms disappeared completely in 12 of 24 patients, and pain relief was seen in 91.7% (22/24). Two cases suffered from residual symptoms. Twenty-two cases obtained complete reduction of olisthy vertebral bodies, and anatomical reduction rate was 91.7%. No infection or neurological complication occurred in this group. In group B, results showed preoperative clinical symptoms disappeared completely in 13 of 21 patients, and pain relief was seen in 90.5% (19/21). One case suffered from residual symptoms. Twenty cases obtained complete reduction of the olisthy vertebral bodies, and anatomical reduction rate was 95.2%. Four cases of infection or neurological complication occurred in this group. Both groups indicated no significant difference in clinical outcomes and anatomical reduction rate during follow-up. But group A had better intraoperative circumstances and postoperative outcome than group B, while group B had better postoperative parameters in X-ray of Angle of Slipping and Disc Index than group A., Conclusions: The first choice of surgical method for lumbar stenosis with low degree lumbar spondylolisthesis is instrumented posterolateral fusion. Only when patients suffer from severe preoperative disc degeneration and low back pain or intervertebral instability should we consider indications for additional use of CAGE.

Background: Cysts of the ligamentum flavum are rare and unusual causes of spinal compression., Methods: We report our experience of four cases of ligamentum flavum cysts occurring in the lumbar spine and discuss some of the possible etiologies and pathophysiologic mechanisms according to the available literature., Conclusion: This entity is clearly different from the synovial facet-joints or ganglion cysts.

Study Design: A pathologic study of the ligamentum flavum in degenerative lumbar disease., Objectives: To elucidate the clinical significance of each pathologic finding of the ligamentum flavum., Summary of Background Data: In many reports, researchers observed the ligamentum flavum removed partially during surgery and did not evaluate the whole image of the ligamentum flavum. In addition, there are only a few reports that examined the possible association between various histologic findings and clinical findings. And, thus, there are many unclear points in the clinical significance indicated by each pathologic finding., Methods: The study participants were 50 patients with degenerative lumbar diseases who underwent surgical decompression with removal of the ligamentum flavum of the affected spinal level. Tissue specimens of the removed ligamentum flavum in cross section were prepared, and changes in the elastic fibers and collagen fibers were evaluated in three grades to evaluate the whole image. In addition, we observed the presence or absence of any focal lesions and statistically analyzed the possible association between these histologic findings and clinical symptoms or image findings., Results: In regard to the association between histologic findings and clinical symptoms or image findings, calcification was observed in significantly older patients, who tended to have low scores in preoperative JOA score, and was frequently observed in patients with cauda equina symptoms. Patients with ossification had a significantly greater % slip, and chondroid cells were frequently observed in patients with spondylolisthesis., Conclusion: Various pathologic findings provided important foundations for discussing the pathogenesis of lesions in ligamentum flavum. Calcification was frequently observed in elderly patients and those with cauda equina symptoms, and these patients tended to have severer preoperative symptoms. Chondroid cells were frequently observed in patients with spondylolisthesis, and patients with ossification had a greater % slip, suggesting involvement of mechanical load in ossification of ligaments. The pathologic findings were significantly related to the clinical features, and these findings will be profitable for understanding the pathogenesis of degenerative lumbar disease.

The purpose of this retrospective study was to analyze clinical results and radiographic findings in patients who underwent surgical enlargement of the lumbar spinal canal combined with resection of the posterosuperior margin underneath the slipping vertebral body for the treatment of lumbar canal stenosis due to degenerative spondylolisthesis. A series of 64 patients who were observed for 3 years or more after operation were examined. The mean age at the time of operation was 64.2 years. The follow-up period was 3-17 years. The Japanese Orthopaedic Association (JOA) score increased from 14.9 points before operation to 25.4 points at the time of the study on average. The general improvement rate was 75.6%. The height and range of motion of the enlarged intervertebral disc were mildly to moderately decreased, and it was found there was a small effect on the adjacent intervertebral disc. On computed tomography, the total level of the enlarged region of the posterosuperior margin increased from 184.4 mm(2) to 339.1 mm(2) on average, but the area of the resected region was 163.3 mm(2) and accounted for 48% of the postoperative area of the spinal canal in the posterosuperior margin. This enlargement of the spinal canal was maintained along the dural canal, and physiological morphology was established. By surgically enlarging the lumbar spinal canal combined with resecting the posterosuperior margin underneath the slipping vertebral body, concomitant repositioning or spinal fixation was unnecessary.

In this paper, the influence of the orientation of intervertebral facet joints in segment L4-L5 on the development of degenerative spondylolisthesis is presented. Thirty one patients over 45 years old, who were operated because of back pain in spondyloarthrosis, were analyzed. All patients were divided into two groups. The first group consisted of the patients with degenerative spondylolisthesis at the level L4-L5. The second group consisted of the patients who were operated because of stenosis without instability at L4-L5. The significant differences in the sagittal orientation of facet joints were stated. We confirmed that the presence of more sagittaly orientated facet joints has influence on degenerative spondylolisthesis. Lack of the increase in value of this angle in patients with degenerative changes without instability allows to suppose that this process is not the result of arthritic remodeling.

Study Design: A retrospective review was completed on 21 patients who had a "least invasive" (one or two level) microdecompression and uninstrumented single-segment lumbar fusion for spinal canal stenosis with degenerative spondylolisthesis., Objective: To determine whether a "least invasive" approach to lumbar spinal canal stenosis and degenerative spondylolisthesis would yield acceptable results., Summary of Background Data: The prevailing surgical technique for symptomatic spinal canal stenosis with degenerative spondylolisthesis is a wide midline decompression and instrumented fusion., Methods: On an average of 38 months postoperatively, 21 patients were personally assessed on four scores: 1) their overall satisfaction with the outcome of surgery, 2) an analog back and leg pain scale, 3) a functional evaluation scale, and 4) Ferguson (upshot) anterior-posterior lumbosacral and lateral flexion-extension radiographs., Results: The overall satisfactory outcome on all four scales was 16 (76%) of 21. Twenty of twenty-one patients had relief of their claudicant leg pain; the overall fusion rate was 18 (86%) of 21. Two of three patients with a pseudarthrosis had a successful outcome on the patient-oriented outcome (1, 2, and 3) scales (excluding the radiograph scale), and one was a failure. One patient with a solid fusion was a failure because of continuing back pain. One patient with a solid fusion was a failure because of continuing leg pain. The overall satisfactory outcome on the nonradiographic scales was 18 of 21, for an 86% patient satisfaction rate., Conclusions: In this retrospective study, a "least invasive" surgical approach to lumbar degenerative spondylolisthesis with spinal canal stenosis causing claudicant leg pain produced acceptable results.

Purpose: To study the relationship of lumbar facet joint tropism to degeneration of the cartilage and subcortical bone in the facet joints and the effect of tropism in intervertebral disk degeneration., Methods: The orientation of 104 cadaveric lumbar facet joints with respect to sagittal plane was measured on CT scans, and the joints were classified as having no tropism, mild tropism, or severe tropism. On MR images, the severity of cartilage degeneration and bony sclerosis was measured. The correlation between tropism and degeneration was calculated, as was the relationship among age, spinal level, and degeneration., Results: We identified four spinal levels with severe tropism, six with moderate tropism, and 94 without tropism. Cartilage degeneration was not significantly more severe in the joints with tropism than in the joints without. Sclerosis was slightly greater in the joints with tropism than in the joints without it. Sclerosis and cartilage degeneration were significantly related to age and spinal level., Conclusion: Age, spinal level, and overall facet joint angle are more important factors in facet joint degeneration than is tropism.

The pre- and postoperative lumbar spine radiographs of 119 patients who underwent decompressive lumbar laminectomy were studied to evaluate radiographic changes and to correlate them with clinical outcome. An accurate and reproducible method was used for measuring pre- and postoperative radiographs that were separated by an average interval of 4.6 years. Levels of the spine that underwent laminectomy showed greater change in spondylolisthesis, disc space angle, and disc space height than unoperated levels. Outcome correlated with radiographic changes at operated and unoperated levels. This study demonstrates that radiographic changes are greater at operated than at unoperated levels and that some postoperative symptoms do correlate with these changes. Lumbar fusion should be considered in some patients who undergo decompressive laminectomy. The efficacy of and unequivocal indications for lumbar fusion can only be determined from randomized, prospective, controlled trials, however, and these studies have not yet been undertaken.

Anatomic variations exist in the facet joint orientation, shape, and size at L4-5. This morphology is further modified by degenerative changes in spinal stenosis and degenerative spondylolisthesis. This study explored the morphologic alteration of "pedicle-to-pedicle" decompression on the facet joints in normal patients, spinal stenosis patients, and degenerative spondylolisthesis patients. Using computerized digitization, computed tomographic scan images of the facet joint at L4-5 and the medial border of the pedicle at L5 were superimposed. The facet joint orientation, coronal dimension, percentage, and absolute reduction in coronal dimension after pedicle-to-pedicle decompression, and residual coronal dimension after decompression at L4-5 were measured for the three groups. There is a significantly reduced coronal dimension of the facet joint in degenerative spondylolisthesis patients compared with spinal stenosis and normal patients (P < 0.01). The average reduction of the facet joint coronal dimension is 34% (SD 30%) in degenerative spondylolisthesis, and 36% (SD 25%) in spinal stenosis. The smaller preoperative coronal dimension in degenerative spondylolisthesis leads to a significantly reduced residual coronal dimension in degenerative spondylolisthesis compared with normal patients (5.9 mm [SD 4.3 mm] vs. 9.3 mm [SD 3.5 mm]), respectively. Wide variations in facet joint reduction and residual facet joint coronal dimension exist. The significantly reduced coronal dimension after decompression in degenerative spondylolisthesis may be correlated to a trend to further anterior displacement if it is treated with decompression alone. Case-specific assessment of residual facet joint morphology after decompression in both spinal stenosis and degenerative spondylolisthesis patients should be integrated into decisions about fusion for stability at the L4-5 level.

This study examined the role of facet joint morphology in the etiology of both degenerative spondylolisthesis and isthmic spondylolysis. To this end, the axial facet joint morphology of the lower lumbar spine in a normal population and in populations of patients with spinal stenosis or degenerative spondylolisthesis at L4-5 and in patients with isthmic spondylolysis at the L5 level were characterized. Computed tomographic scans were digitized, defining the axial morphology of the normal facet joint at five stations from proximal to distal within the joint. Assessments were made of facet joint orientation, transverse articular dimension, depth of the articular surface, and shape of the articular surface at levels L3-4, L4-5, and L5-S1. There was a gradually more coronal orientation from proximal to distal among the stations at each level, and a maximal transverse articular dimension at the level of the superior endplate of the caudad vertebra. Minimal error in the recording process at this level. In addition to the maximal joint dimension, made this level the most representative of the overall morphology and most useful for further studies. At the L4-5 level, a significantly more sagittal facet orientation was found in the degenerative spondylolisthesis group when compared to both the normal population and spinal stenosis groups (P < 0.01). At L5-S1, the only significant morphologic difference between the normal population and the patients with isthmic spondylolysis was reduced transverse articular dimension. These results support the hypothesis that patients developing degenerative spondylolisthesis are predisposed to this by a developmental sagittal orientation of the L4-5 facet joints.

Degeneration starts in one joint and eventually involves all three joints of the three-joint-complex (one disc and two posterior joints) at an intervertebral level. Later, mechanical changes occur that affect the levels above and below and cause similar changes there. The result is multilevel lumbar spondylosis and stenosis. The spectrum of degenerative changes in a three-joint-complex progresses through three stages, which help to predict the outcome of different types of treatment.